Volume 39 ·  Issue 12 ·  2003

Human visual plasticity was studied by the observation of the effects of treatment in teenage and adult amblyopia.

One hundred and two cases (125 eyes) were diagnosed as amblyopia according to the national criteria of amblyopia. These patients were divided into teenage group (15-17 years old, 47 cases and 57 eyes) and adult group (18-45 years old, 55 cases and 68 eyes). Eye examination, including best correct visual acuity, laser interference fringes visual acuity (IVA), degree and patterns of amblyopia, and nature of fixation were performed in these two groups before amblyopic treatment. Patients were treated with correct spectacle, optical and drug penalization (including far and near penalization, as well as light penalization), combined with occlusion and assisted with red light pleoption. All patients were followed up for 1-5 years, with an average of 2.9 years.

Fifty five eyes (44%) were cured (23 eyes recovered, 32 eyes basically cured), 37 eyes (29.6%) were improved, 33 eyes (26.4%) were nullified and the total improvement rate was 73.6%. Different ages did not influence the results of treatment significantly (P> 0.05). Outcome of foveal fixation and parafoveal fixation was much better than that of paramacular fixation and peripheral fixation (P< 0.005). The curative efficiency of amblyopia was also dependent on the degree of amblyopia (P< 0.005). Curative effects of ametropic and anisometropic amblyopia were better than that of strabismic and deprivable amblyopia (P< 0.01). Visual acuity predicted by IVA before the treatment was the same as real results after the treatment in 112 eyes among 125 eyes (92.8%). The correlation efficient between the predicted and real vision was statistically significant (r = 0.886 2, P< 0.000 1).

Vision in most teenage and adult amblyopia can be improved by amblyopic therapy. Therefore, it seems that human visual plasticity exists permanently during the whole life. Visual acuity after the treatment can be predicted by pre-treatment IVA.Results of amblyopia treatment are closely related with the degree and patterns of amblyopia and are also dependent on the cooperation of the patients.

To evaluate the significance of Orbit™ 1.8 Computer Biomechanics Simulation in the diagnosis and treatment of congenital superior oblique paresis.

Fifteen patients with congenital superior oblique paresis were enrolled in the present study. Hess test and other strabismus tests were performed before and after the surgery. Parameters such as contractile force, elasticity, innervation of extraocular muscles and the secondary changes in other muscles were treated by the Orbit™ 1.8 to simulate the preoperative situation. A biomechanical strabismus model was created. Surgical manipulations were tested on the model to predict postoperative outcomes. After surgery, simulated and actual outcomes were compared.

The predicted results matched with the actual results quite well. Before the surgery, the mean difference between these two data was 1.66°±0.44° in horizontal and 1.97° ±0.51° in vertical gaze. After surgery, mean difference in horizontal and vertical gaze of these two data was 1.21°±0.34° and 1.59°± 0.41°.

Orbit™ 1.8 Computer Biomechanics Simulation offers a biomechanical approach to understand all of the forces that combine to control eye movement and how these forces interact in normal eyes and in eyes with motility problems. It can be used to reflect the causes of strabismus, to design the surgical procedure, to verify the diagnosis and to predict the outcome of surgery. It is a helpful tool in the diagnosis and treatment of ocular motility disorders.

To investigate the postoperative changes of the head tilt test in patients with unilateral congenial superior oblique palsy.

Thirty-eight cases with congenital unilateral superior oblique palsy underwent the ipsilateral inferior oblique or/and contralateral inferior rectus weakening procedure. Bielschowsky head tilt test was evaluated quantitatively before and after the operation by the prism cover test while the patient fixated at 33 cm and 6 m on the small light target. A positive Bielschowsky head tilt test was defined as one in which the vertical deviation when the head tilt to the side of the paresis was at least 5.0^△ greater than that on tilt to the uninvolved side.

Before the operation, the hyperdeviation of the involved eye was 3.0^△-25.0^△ (average 11.0^△) in primary position. The deviation on tilt to the side of the paresis was 23.0^△ (15.0^△-40.0^△) and the deviation on tilt to the uninvolved side was 2.5^△ (0.0^△-10.0^△). A positive Bielschowsky tilt test was found in all cases preoperatively. After the operation, the hyperdeviation of the involved eye was 0.0^△-5.0^△ (average 2.0^△) in primary position. The result of Bielschowsky tilt test was still positive in 34 cases and negative in only 4 cases.

In most cases with unilateral superior oblique paresis, the results of Bielschowsky tilt test do not change to negative postoperatively. The significance of using this test for evaluating surgical results remains to be determined.

To investigate the results of using shifting fixation eye to manage monocular or asymmetrical binocular dissociated vertical deviation (DVD).

Twenty-three DVD children whose corrected vision was better than 0.5 in the amblyopic eye were studied. The goal of the shifting fixation eye was gained by decreasing the vision of the primary fixation eye to 2 or 3 lines (Snellen Visual Acuity) lower than that of the fellow fixation eye by occlusion or optical methods. The vision, alignment and retinal correspondence were evaluated before and after the treatment.

After the treatment, in 10 patients, the vision of the primary fixation eye did not decrease significantly and the vision of the fellow eye increased 2 lines. In 19 patients, a cosmetic result was achieved; the primary fixation eye was shifted in 4 patients that had similar hepertropia in two eyes (≤10^△). Normal retinal correspondence was restored in 3 patients who had normal retinal correspondence at near while depressed at distance.

Shifting fixation eye is an effective treatment for DVD hepertropia, especially in patients with monocular or asymmetrical binocular DVD with hepertropia in one eye and latent hepertropia in the fellow eye. This method is suitable to DVD children who do not accept the surgical treatment and have slight to moderate amblyopia and ametropia.

To explore the mechanism and therapy of strabismus secondary to ophthalmic surgeries.

79 cases of postoperative secondary strabismus were examined for eye position, eyeball movement, diplopia and ocular muscle traction test. Strabotomies were performed in some of the cases. Their involved extrocular muscle conditions were examined during the surgery.

The cases of strabismus in the series were secondary to surgery of retinal detachment (38.0%), cataract extraction (31.7%), orbital surgery (13.9%), and other ophthalmic surgeries such as glaucoma, pterygium and blephatoptosis. Some cases secondary to surgery of retinal detachment and cataract extraction didn't recover in more than 6 months after surgery. The traction tests of involved muscles in some cases were positive. Fibrosis of the involved ocular muscles and adhesion of involved ocular muscles to conjunctiva, sclera and explants were found during strabotomies. Strabismus secondary to orbital surgery mainly showed impeding movement of eyeball. Strabismus secondary to pterygium mainly related to injury of the medial rectus operations. Strabismus secondary to glaucoma surgery recovered spontaneolusly in 2-14 days after operations.

Intraocular or external ophthalmic surgeries can cause secondary strabismus. The mechanism is primarily due to direct injury of the extraocular muscles, impeding movement and mechanical compression to the eyeball. Surgeons should pay more attention for those side effects, and take effective therapy to prevent and treat iatrogenic strabismus.

The purpose of the present study was to explore the reliability of successive automated static perimetry in suspect and manifest glaucoma patients.

Retrospective investigation was performed on 82 glaucomatous eyes and 80 suspect glaucoma eyes which were tested twice or more during Aug 1994 and June 2000 with the Octopus 1-2-3 automated perimeter. False-positive response rate (FP), false-negative response rate (FN) and reliability factor (RF) were calculated and analyzed.

According to the reference criterion provided by the manufacturer (Interzeag company), in suspect glaucoma patients, only 5.1% visual field test results (8 eyes) were unreliable, while the unreliable rate was 18.1% (20 eyes) in manifest glaucoma patients. FP, FN and RF all had highly skewed distributions in each subgroup of suspect and manifest glaucoma patients. The FN of each subgroup of manifest glaucoma patients was significantly higher than that of suspect glaucoma patients (P< 0.01).

Automated perimetry can provide a reliable result in most suspect glaucoma eyes. A few unreliable results may be regarded as sporadic events. FN in glaucoma patients are related to the status of visual field defects.

To compare the aqueous humor penetration of topically applied ofloxacin, ciprofloxacin and tobramycin in human eyes.

Senile cataract patients (125 eyes in 125 cases) receiving phacoemulsification were randomized into three groups: ofloxacin, 42 eyes; ciprofloxacin, 41 eyes and tobramycin, 41 eyes. Each group was randomized into five sub-groups, with 8 or 9 eyes in each sub-group. Each group received either 0.3% ofloxacin, ciprofloxacin or tobramycin topical drops preoperatively. Eyedrops were instilled one drop every 15 minutes for six times. Aqueous samples were obtained from different sub-groups during surgery, 7.5, 15.0, 30.0, 60.0 and 120.0 min after the last drop, respectively. Concentration of the antimicrobial agents was determined by the HPLC (high pressure liquid chromatography).

Aqueous humor concentration of ofloxacin was significantly higher than that of ciprofloxacin at the same period after the last drop. The bioavailability of ofloxacin was 6 times that of ciprofloxacin. Tobramycin could not be detected by HPLC, so its concentration was lower than the minimum detectable level by HPLC (0.05 μg/ml).

Ofloxacin has the best aqueous penetration in human eyes, as compared with ciprofloxacin and tobramycin, which suggests ofloxacin could be the preferred topical medicine for the prevention and treatment of endophthalmitis.

To investigate the effect of vitrectomy combined with full endocular panretinal photocoagulation in patients with late stage of proliferative diabetic retinopathy (PDR).

Pars plana vitrectomy combined with full panretinal photocoagulation were undergone in 56 eyes (56 cases) with late stage of PDR, including 32 eyes with tractive retinal detachment. Preoperative and postoperative visual acuity, anterior segment by slit lamp and fundus examination by indirect ophthalmoscopy, as well as fluorescein angiography (FFA) were analyzed.

Retina were reattached in 52 eyes. Vitreous hemorrhage, retinal bleeding, exudation and neovascular changes were not observed in these eyes. Non-irrigated areas were not found in 28/32 eyes in which FFA examination has been performed. Final visual acuity was improved in 52 eyes.

Full endocular panretinal photocoagulation with low energy is an effective and safe procedure with low rate of complications for the late stage of PDR.

To discuss the incidence rate and causes of endophthalmitis caused by minor ocular perforation. To document its damage to the visual function, so as to improve the rate of prevention of this disease.

The following clinical information of 153 cases with minor ocular perforations from a retrospective study was collected: general conditions, injury objects, wound shape and size, presence or absence of ocular foreign body, associated organic injuries, visual functions in the early stage after injury, speed of occurrence of infection, and positive rate of microbiological tests. The results with the drug treatments and surgical therapy were analyzed.

All of 153 cases were followed up from 3 months to 7 years. The visual acuity in 13 cases (8.5%) was over 0.3. 140 cases (91.5%) were less than 0.3. Enucleating was performed in 37 cases (24.2%).

The patients with minor ocular perforations tend to have good visual acuity in the early stage after injury. But their visual acuity was lost in 4 to 12 hours if rapid and severe infections occurred. The risk of endophthalmitis should be recognized and evaluated on time in the early stage after injury.

To analysie the ultrastructure and cytokines expression from cultured orbital fibroblasts (OFs) in the patients with thyroid-associated ophthalmopathy (TAO).

Primary cultured OFs were obtained from 5 patients with TAO and 4 normal control subjects, some of subcultured OFs were treated by patients' serum with active TAO. Ultrastructures of OFs were observed by transmission election microscope. The cytokines in cultured supernatant were detected by enzyme linked immunosorbant assay (ELISA).

There were no significant differences of ultrastructure of OFs from TAO patients and normal subjects. Nucleoli enlargement, microvillus prolongation and increase of endoplasmic reticular of OFs were detected after maitaining in culture. The IL-1, TNF-α and IFN-γ were found in supernatant of OFs treated by patients' serum. IL-1 was found in supernatant of OFs in TAO patient and control subjects, and the IL-1 level of former was higher than the controls.

There are no significant differences in ultrastructure of OFs from patients with TAO and normal subjects. The OFs treated with the serum of TAO patients showed proliferation and increasing cytokines secretion.